Detection of GeV emission from an ultralong gamma-ray burst with the Fermi Large Area Telescope
Detection of GeV emission from an ultralong gamma-ray burst with the Fermi Large Area Telescope
GRB 220627A, detected by Fermi Gamma-ray Burst Monitor (GBM), is a potential gravitationally lensed gamma-ray burst (GRB), because it has two similar episodes in terms of temporal shapes and spectra. However, by analyzing data from the Fermi Large Area Telescope, we found significant differences in gamma-ray photon numbers between the …